The Yeomanry Mounted Brigade was formed in
Egypt on 19 January 1915. It commanded the
1/1st Hertfordshire Yeomanry and the 1/
2nd County of London Yeomanry (Westminster Dragoons) which had arrived in Egypt on 25 September 1914. Brig-Gen J.D.T. Tyndale-Biscoe was appointed to command. It joined the
2nd Mounted Division on 13 August and was dismounted to take part in the
Gallipoli Campaign. Each regiment left a
squadron headquarters and two
troops (about 100 officers and men) in Egypt to look after the horses. While with the 2nd Mounted Division, the brigade was designated as
5th Mounted Brigade. Due to losses during the
Battle of Scimitar Hill and wastage during August 1915, the
2nd Mounted Division had to be reorganised. On 4 September 1915, the
1st Composite Mounted Brigade was formed from
1st (1st South Midland),
2nd (2nd South Midland) and 5th (Yeomanry) Mounted Brigades. Each dismounted brigade formed a battalion sized unit, hence
5th Yeomanry Regiment.
Egypt 5th Yeomanry Regiment left
Suvla on 31 October 1915 for
Mudros. It left Mudros on 27 November, arrived
Alexandria on 1 December and went to Mena Camp,
Cairo. The brigade left the 2nd Mounted Division on 7 December, was reformed and remounted, and joined the
Western Frontier Force. By March 1916, the brigade had been broken up as the Hertfordshire Yeomanry was split up as divisional cavalry and the 2nd County of London Yeomanry was attached to the
6th Mounted Brigade, still in the Western Frontier Force. ==Commanders==